In telecommunications, it is frequent to describe a digital transmission by three elements, a sender, a receiver and a transmission channel. FIG. 1 provides a symbolic and simplified description of a sender 10 which transmits a coded signal through the transmission channel which will be decoded by the receiver 20. To augment the robustness of the transmission and overcome disturbances, there are known ways for those skilled in the art to include, in the signal to be transmitted, an error-correcting code aimed at reducing errors at reception.
Since error-correcting codes are presently essential for ensuring reliable transmission, total control and freedom during the implementation of the codes are crucial given the huge increase in standards, networks and hardware. In all the standards used, the preferred approach is that in which the sender and the receiver agree on the error-correcting code, either by fixing it once and for all, or by plain (or unencrypted) transmission of the encoding scheme and the code used. Although this approach forms the basis of classic communications, it is limited in that the codes chosen are part of a very restricted, fixed and unchanging list.
In order to improve digital transmission and overcome the above drawbacks, another solution consists in getting rid of the need for any preliminary agreement between the sender and the receiver on the error-correcting code used. This technique provides for flexibility in the management and dynamic control of networks by reducing or even eliminating problems of compatibility related to the diversity of present-day and future connected apparatuses in making them self-configuring from the viewpoint of the correcting codes used. In the transmission systems that have been conceived, the reception device must be configured in such a way that it can blindly identify the sender's parameters.
To date, there are certain number of existing blind detection techniques such as those proposed especially by Melanie Marazin et al. in “Dual Code Method for Blind Identification of Convolutional Encoder for Cognitive Radio Receiver Design” and “Reconnaissance en aveugle de décodeur à base de code convolutif: Contribution à la mise en ceuvre d'un récepteur intelligent” (“Blind recognition of decoders based on convolutive codes: Contribution to the implementation of a smart receiver”). However, the performance levels of the published algorithms are fairly limited. In particular, these algorithms work in configurations that take account of strong assumptions on the type of code used as well as the type of error envisaged. They therefore address a specific and limited type of error-correcting codes. Furthermore, the technical solutions proposed process only binary strings that contain few errors and have a known structure as regards parameters of segmentation length and/or synchronization. They do not work in flow conditions either, and are useful only in the post-processing of data.